Improvement in casting brass and other metals



CASTING BRASS AND OTHER METALS.

Patented June 19, 1877.

UNITED STATES PA EN OFFIGE JAMES R. COOPER, OF FRANKLIN TOWNSHIP, OAKLAND COUNTY, MIOH.

IMPROVEMENT m CASTING BRASS AND OTHER METALS.

Specification forming part of Letters Patent No. 192, 114. dated June 19,1877 application filed June 9, 1877.

To all whom it may concern Be it known that I, JAMES RENWICK COOPER, of Franklin township, in the county of Oakland and State of Michigan, have in vented certain new and useful Improvements in. Casting Brass and other Metals and I do hereby declare that the following is a full, clear, andexact description thereof, which will enable others skilled in the art to which it pertains to make and use the same, refer afterward wrought.

In the ordinary way of casting brass for rolling purposes there is great loss and inconvenience from the fact that the metal unites with the oxygen of the atmosphere the moment it strikes it. As soon as the metal comes in contact with the atmosphere a coating of oxidized metal is formed instantly, and while the metal is being poured into the surfaces are exposed to the air. This oxidized portion is a thin film upon the surface of the metal, and when the metal is poured into the molds a coating of oxide forms about and encircles the stream of metal. The oxide thus formed is constantly breaking away and falling into the mold, where it becomes more or less broken up and mixed with the metal.

The molds for casting this metal in all its forms are made of cast-iron, and it is the practice of the manufacturers to grease the inside of the molds with some of the common and cheap kinds of grease. At the temperature necessaryfor the proper mixing and pouring of these metals, which usually ranges from 2,300 down to1,800, zinc is more or less given ofi from the metal as a vapor, and this continues until the metal solidifies, or until the heat is lowered to about the point at which the metal solidifies. While the metal is being poured into the molds, and while these vapors of zinc are being emitted, the surfaces of the molds are sufliciently cool to condense these vapors, and they are condensed and deposited in the 'ture.

heavy oil or grease that is used in greas-' ing the molds Thisgrease burns to lampblack, and this lamp-black, together with the condensed zinc-vapor, form a dark-gray powder upon the metal, which the workmen term dirt. This. admixture of zinc and v carbon is liable to, and does at times, break awayfrom' the surface of the mold and float into the body of the metal, making unsound and porous places therein but thetmost seri; ous loss to the manufacturer is the extreme tendency of the metal to unite with the oxygen of the atmosphere.- The tendency of this film of oxidized metal is to be deposited upon the outside of the bars; and if it were all there and lay smoothly upon the bar, it would do little or no harm, but much of it is inclosed in the metal, and that which is upon the outside is compressed and crimped together in such a manner that it sometimes extends to a depth of one-fourth of an inch, and at times to such an extent as to ruin the metal for the purpose for which it was designed.

The bars of brass, after leaving the castingroom,are taken to the rolls and brought down to a certain thickness. They are then" taken to molds this oxidation still goes on as fast as new machines with curved sharp scratchers or scrapers, which cut the metal into thin shavings and work upon any part of the bar that the op-f' erator may direct. They are then passed to workmen with sharp instruments to be scraped by hand until they are considered sufiiciently clean to produce a good article of manufac- There is often ten, fifteen, or twenty per cent. of the metal scraped away. That portion of the oxidized metal that is inclosed in the body of the bar causes a cavity, and when rolled into a thin sheet is very .much enlarged, and when annealed the sheet blisters at that point, and is rendered worthless except for resmelting.

My invention has for its object the remedying of the defects above enumerated, which exist in the modes of casting metal, as heretofore practiced. In order to remedy these defects it is not only necessary to expel the air from the mold, but quite as necessary to keep it from the mouth of the crucible while the metal is being poured therefrom into the mold; and to'effect this my invention consists in creating and maintaining at the mouth of the mold a flame that will encircle or partially encircle the molten metal during the whole time that the mold is being filled there'- with.

In the accompanying drawing, Figure 1 is a perspective view of the mold; Fig. 2, a section thereof, and Fig. 3 a modification of the channel for supplying gas to the mouth of the mold.

The letter A designates a grooved collar or cap, which is susceptible of being easily placed in position around the mouth of the mold B, or removed therefrom, and is to contain alcohol, benzine, or any light oil that will produce a reducing-flame a sufficient length of time to allow the workman to fill a mold in the ordinary time required therefor.

Immediately before the mold is filled I throw around its mouth a light spray of alcohol, benzine, or any light substance that will produce instantly a flame, so that the flash thus created will expel the air from the mold, and also from about the exit of the sn perposed ladle, and the flame which is maintained will create suflicient heat to carry off any vapors of zinc that may be emitted from the metal, and thereby prevent their condensation upon the inside of the mold, which condensation would be productive of the pernicious and vicious results set forth in the first part of this specification.

It would be well that whatever is used to produce the flame for the protection of the metal being poured into the mold should be snfficiently inflammable to produce a flame from the heat of the crucible or pot at its ordinary temperature, whereby is avoided the necessity for lighting the material, and the best results insured, inasmuch as the flash is produced at the exact time that it is needed.

I do not confine myself to the materials named, n'br to any particular material, for the production of the reducing-flame; nor do I confine myself to any special mode or appa- 'ratns for holding the material, although I prefer to use the grooved cap shown. in the drawing. Where gas can be had there could be a convenient device-something like that shown-for furnishing the flame, so that, by

means of a tube connecting this channel with a gas-reservoir, the necessary supply will be furnished.

pors from a mold by producing one or more momentary flashes or flames within the mold, or at the mouth of the mold, while the metal is being poured; but

What I do claim is- 1. The within process of casting brass and other metals, which consists in creating and maintaining at the mouth of the mold aflame that willencircle or partially encircle the molten metal during the whole time that the mold is being filled therewith, so as to expel air from the mold and carry off the vapors evolved from the metal, thereby preventing their condensation within the nold, as well as preventing the oxidation of the molten metal, substantially as set forth.

2. A mold for casting brassv and other metals, provided with a device for maintaining a reducing-flame at the mouth of the mold,substantially as set forth.

In testimony that I claim the foregoing as 'my own I aflix my signature in presence of two witnesses.

JAMES R. COOPER.

' Witnesses:

WM. G. HENDERSON, WILLIAM FIToH. 

